A network such as a telecommunications network typically contains a number of performance management tools for monitoring the performance of the network. These tools are used to monitor the performance of various aspects of the network, for example, the number of telephone calls dropped in a particular cell of a cellular telephone network. The user of the performance management tools has control over the selection, activation and deactivation of performance measurement reports in the network.
Default performance measurements are selected from the performance management tool in order to monitor the network performance at all times.
Performance threshold measurements may be used to indicate potential problems in the network when a measurement drops below or increases above a predetermined threshold level. Examples include: the number of dropped calls in a particular cell exceeding an acceptable threshold level; the signal-to-interference ratio on a radio link crossing a certain threshold, thereby indicating poor voice quality for a mobile user; the amount of traffic in Kbytes per second (Kbps) falling below a certain level, indicating a possible dead or dying cell; the number of packets for a packet data user having a time delay greater than a certain time threshold (the latter example also indicating that too many users have been allowed access to the network).
EP 0,347,360 is an example of a system for isolating and diagnosing problems in a data communication network.
While the performance measurements mentioned above are useful for indicating potential problems arising in the network, there is no means of automatically activating other, more relevant, performance measurements, so that the potential problem area can be observed further.
U.S. Pat. No. 5,638,514 is an example of a system for supervising network equipment, with the aim of reducing the amount of performance data being gathered. This is achieved by updating a status table in accordance with the performance data being gathered. However, this system requires a complex hierarchical system for minimising the amount of performance data being gathered.
The aim of the present invention is to overcome the disadvantages associated with the prior art by providing a network management system and method in which a group of performance measurements are activated and/or deactivated in response to performance measurement thresholds being crossed.